The commander of U.S. forces for Africa, Army General Carter Ham, said Monday that the U.S. military is increasing its operations on the continent as terrorist groups begin to work closer together to carry out attacks in the region.

The head of the U.S. Africa Command, General Carter Ham, said the terrorist threat in Africa is growing and that U.S. forces under his command are focused on three main groups: al Shabab in East Africa, al-Qaida in the Islamic Maghreb in the north, and Boko Haram in Nigeria.

“Each of those three organizations is by itself a dangerous and worrisome threat. What really concerns me are the indications that the three organizations are seeking to coordinate and synchronize their efforts, in other words, to establish a cooperative effort amongst the three most violent organizations. And I think that’s a real problem for us and for African security in general,” Ham said.

Ham told African military officers meeting near the Pentagon that U.S. commanders have indications that the three groups are likely sharing funds and training in using explosive materials.

The United States’ new defense strategy calls for a greater focus on Africa, but only with a limited presence of U.S. personnel there to train and assist the militaries of African countries counter security threats.

Last year, President Barack Obama authorized the deployment of about 100 U.S. troops to the region to help the armed forces of Uganda, the Democratic Republic of Congo, South Sudan, and the Central African Republic in their campaign against rebel leader Joseph Kony and his Lord’s Resistance Army, or LRA.

Ham said that enabling the militaries of partner nations is a more effective approach than sending U.S. forces to do the work in the vast area where the LRA is operating.

“We can help in terms of logistics, some information and intelligence sharing, of communications, and a little bit of mobility. I think that’s the best way for us to provide what I would term unique U.S. military capabilities to assist our African partner,” Ham said.

In efforts like the hunt for Joseph Kony, General Ham said U.S. forces engage in surveillance activities, but he noted that happens only with the consent of host countries.

The United States has only one permanent military base in Africa, in Djibouti, with about 2,000 American personnel. Ham said there are no plans to build any other base on the continent.